Concentration of ores by flotation



Patented Dem 1'5, 1942 v 2,305,032 CONCENTRATIONOF oans BY norarron Chester L. Read, Westfleld, N. 1., asslgnor to Standard Oil Development Company, a corporation or Delaware NoDrawing. Application May 15, 1940.

. Serial No. 335,335

20mins. (chaos-1st) This invention relates to improvements in processes of ore concentration and particularly in mineral oils used for concentrating ores by flotation. f

It is known that the phenomena of flotation are not entirely physical in their nature. Chemical reactions play a large part in flotation processes so that by adding certain reagents the operation can be modified or completely changed. in selective flotation, minerals are made to float )r not to float by the use of various reagents vhich produce deflniteeffects on the surface ihases of the mineral particles. When reagents If one class are absorbed by certain mineral )aI'tiCIGS, the mineral particles at the same time ibsorb gases, that is, the reagent tends to m the particle of mineral which in turn attracts a bubble film, and as a result the mineral particle acquires sumcient buoyancy to float on the liquid and be removed with the froth. The term."oil" in flotation has been gradually acquiring the meaning of hydrocarbon oil free of polar groups. As such, the use of oils in flotation. of sulfide ores has been decreasing. both as a relative and absolute basis. 'The'hydrocarbon oils arenot collectors but are considered as protectors'or coatings that are formed by collectors.

It is an object of this invention to provide a petroleum 'oil or petroleum oil derivative that 'is more chemically active and will serve as a collector in cleaner separation of a mineral ore from the gangue. 1

concentrated sulfuric acid is diluted with water and allowed to settle. The separated aqueous acid layer is removed and the oillayer having a specific gravity of 1.0607 and an acid content of 15.4% is washed with 40 Be. aqueous solution of sodiumhydroxide. The oil is made slightly basic, 1% sodium hydroxide in excess of that According to this inveiitio sludge resulting.

from the acid treatment 01' naphthas or other light petroleum distillates containing 0.3% of sulfur or more is processed to separate the oil and acid components. The acid sludge is dilutedby adding water" and allowed to settle and stratifyi The oilphase is separated and caustic washed toneutralize and to remove any entrained acid components and further refined by distilling. The distillate obtained is a product having an end point of approximately 700 F. The distillate is extracted with sulfur dioxide. Other preferential solvents, such as phenol, iurfural,

etc., may be used to extract the distillate. The

solvent is then separated from the extracted oil and the solvent-free extract oil is then used as a flotation reagent. For example, acid sludge separated after; treating debutanizer bottoms with i'ective lllfloaull 1301111- assessseeee required for neutralization being The oil in the amount of 2860 cc. is charged to a still, 1060 cc. of water and690 cc. of an oil beingdistilled off leaving a residue of 1110 cc. The oil distillate is a 38.3% yield based on hydrocarbons present and "has a specific gravity of 0.8978 and an aniline point of 57 F., the distillation range being as follows: a

Distillation. range Per cent oil 00% recovery The distillate oil is extracted with sol at -40 F., the rafllnate yield being 56.4% based on the distillate and the extract yield being 43.6%. The solvent is separated from the exit causes to i'roth to some extent. The 10110 ing flotation testswere carried out and the fol:

lowing points were brought out:

(1) The flotation oil acts as a collector for substantially all or the sulflde minerals, such as galena (PbS) chaloocite (CuFeSz), pyrite (Fess) or bornite- (Cum). It seemsparticularly-etslightly soluble in 2 2,soo,osa

Metallurgical am for flotation lam 1| w l Lin/ton 03$- ,rurnyul mam Reagent oiore ibJtcn pH centrato concentrate taiiings ahead 10% GALENA rte) m 0m (8100 01m None. None 0.10. 7.4 Good. xmmm 0.04 010 as 10.1 -....do...-- Under 2%. oilreagenfku..- 0J3 0.10. 8.0 i0.2 d v Do. GALENA res) mp 00% olirlorrn ouoo. can

None 0.10 1 as 0.2 Mod moist-s57. xantbatc 0.08 0.l0 0.7 10.8 Gum I Under 2%. Oilioagent a: 0.10 as ig: 5: 3a

oorrna on: 0.57 noam'rr: (entrust), 00.5% omens ,OSTLY QUARTZ) ms.--" None 0.10 a0 21 Good 70007,. Xanthate- 0.04 0.10 8.9 0.6 do Under 2%. Qilresgcnt 0.0a 0.10 as 0.0 ----do Do.

i Potassium ethyl xanthatc. \j I Petroleum oil. Appeared tobesiight excess of oil. Conditions of tests: mixture to form layers. separating an aqueous Ore charge: j acid layer, neutralizing the oil layer, distilling the Ore (minus mesh) -,8-- 500 oil up to a temperature of 700 F., extracting the Water ..cc... 2150 distillate .with a' selective solvent of the group Pebbles s--- consisting of liquid sulfur dioxide, phenol and Grind for 30 min. in Abbe Trojan-size m furfurol, separating the solvent-and extract and at 84 R. P. M. separating the solvent from the extract to obtain Float in l agergren laboratory flotation ma-' chine (600-gram size):

Agitation with collector addition '-s- .l..

Flotation do..- 6'8 This flotation 011 is also suitable for use in the 40 concentration of molybdenite ore,'graphite and coal. It may also be used in combination with other oils, such as pine oil or mercaptans.

v I claim:

the mineral oil. r

2. A process of effecting the concentration of sulfide minerals, molybdenite ore, graphite and coal, which consists in agitating-and aerating a pulp of the minerals in thepresencemf frothing and collecting agents wherein the collecting agent comprises a mineral oil having a specific gravity of about 0.9163, an aniline point of about 6 F. and a bomb sulfur of about 6.4% and being very slightly soluble in water, the mineral oil.

1. A process of effecting the concentration of 'being obtained by hydrolyzinga sludge produced sulfide minerals, molybdenite ore, graphite and coal, which consists in agitating and aerating a pulp o f,the minerals in the presence of frothihg and collecting agents wherein the collecting agent comprises a mineral oil having a specific being obtained by treating a petroleum oil of high sulfur content with strong sulfuric acid, separating the acid sludge formed, diluting the acid sludge with water, settling the acid-sludge-water by treating sulfur containing mineral oils with strong sulfuric acid, separating the sulfuric acid sludge formed, diluting with water, settling the acid-sludge-water mixture to "form layers, separating an aqueous acid layer, neutralizing the oil layer, distilling the oil up to a temperature of 700 F., extracting the distillate with a selective solvent of the group consisting ofliquid sulfur dioxide, phenol and-furfurol, separating the solvent and extract and separating the solvent from 

